The song was first recorded for his album, "An Evening Wasted with Tom Lehrer." And considering that that was done probably 35-40 years before this, and considering that he'd given up performing a long time earlier before this, as well, it's remarkable how you could close your eyes, and it almost sounds like the original.
This is from a tribute concert in England from Cameron Macintosh, who had produced a revue of Lehrer songs. One oddity: he changes just one word in the song, from "squirrel" to "sparrow". Whether that reference had come culture difference, or he just wanted to change it all these years to another bird, I have no idea.
Anyway, I chose this version for two reasons. The first is because his banter before singing is more fun than in other versions. And the second is the real reason -- the introduction before he comes on stage.
Ah, Spring is here...